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// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/logging.h"
#include "media/tools/shader_bench/gpu_painter.h"
// Vertices for a full screen quad.
static const float kVertices[8] = {
-1.f, 1.f,
-1.f, -1.f,
1.f, 1.f,
1.f, -1.f,
};
// Texture Coordinates mapping the entire texture.
static const float kTextureCoords[8] = {
0, 0,
0, 1,
1, 0,
1, 1,
};
// Buffer size for compile errors.
static const unsigned int kErrorSize = 4096;
GPUPainter::GPUPainter()
: context_(NULL) {
}
GPUPainter::~GPUPainter() {
}
void GPUPainter::SetGLContext(gfx::GLContext* context) {
context_ = context;
}
GLuint GPUPainter::LoadShader(unsigned type, const char* shader_source) {
GLuint shader = glCreateShader(type);
glShaderSource(shader, 1, &shader_source, NULL);
glCompileShader(shader);
int result = GL_FALSE;
glGetShaderiv(shader, GL_COMPILE_STATUS, &result);
if (!result) {
char log[kErrorSize];
int len;
glGetShaderInfoLog(shader, kErrorSize - 1, &len, log);
log[kErrorSize - 1] = 0;
LOG(FATAL) << "Shader did not compile: " << log;
}
return shader;
}
GLuint GPUPainter::CreateShaderProgram(const char* vertex_shader_source,
const char* fragment_shader_source) {
// Create vertex and pixel shaders.
GLuint vertex_shader = LoadShader(GL_VERTEX_SHADER, vertex_shader_source);
GLuint fragment_shader =
LoadShader(GL_FRAGMENT_SHADER, fragment_shader_source);
// Create program and attach shaders.
GLuint program = glCreateProgram();
glAttachShader(program, vertex_shader);
glAttachShader(program, fragment_shader);
glDeleteShader(vertex_shader);
glDeleteShader(fragment_shader);
glLinkProgram(program);
int result = GL_FALSE;
glGetProgramiv(program, GL_LINK_STATUS, &result);
if (!result) {
char log[kErrorSize];
int len;
glGetProgramInfoLog(program, kErrorSize - 1, &len, log);
log[kErrorSize - 1] = 0;
LOG(FATAL) << "Program did not link: " << log;
}
glUseProgram(program);
// Set common vertex parameters.
int pos_location = glGetAttribLocation(program, "in_pos");
glEnableVertexAttribArray(pos_location);
glVertexAttribPointer(pos_location, 2, GL_FLOAT, GL_FALSE, 0, kVertices);
int tc_location = glGetAttribLocation(program, "in_tc");
glEnableVertexAttribArray(tc_location);
glVertexAttribPointer(tc_location, 2, GL_FLOAT, GL_FALSE, 0, kTextureCoords);
return program;
}
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